Technology requirements are continually increasing the numbers of I/O connections needed on MCMs. This is primarily due to increases in the number of VLSI (very large system integration) chips mounted on an MCM, and to increases in the number of circuits per chip, resulting in an increase in circuit packaging density for an MCM.
In this specification, the term "module" includes several levels of packaging, as follows: A "substrate" is the inner-most part of a module; in the preferred embodiment the substrate is primarily silicon or glass-ceramic. A "chip carrier" is a substrate having semiconductor chips placed thereon in a module, and the chip carrier is a higher level of packaging than the substrate. A "housing" is a frame around the chip carrier to seal or protect the chip carrier and is the outer-most part of a module. In the preferred embodiment described herein, the "module" encompasses a substrate, a chip carrier, and a housing, although at times the term module may be used to refer to one of these parts. A module may be refer to as either a single-chip module or multi-chip module (MCM) according to whether its contained chip carrier has single or multiple chips (i.e. a module may contain one or more chips). An example is the commercially-used thermal conduction module (TCM) constructed with alumina substrates, which is a form of MCM. An upper major surface of the TCM is covered with a thermal cooling structure, and the other major surface is covered with conductive I/O (input/output) pins which are used to plug the module into a computer framework. The substrate in a TCM is constructed with many internal layers of wiring to accommodate the interconnections among multiple chips on the upper substrate surface. The TCM has a thin, low profile shape to support internal cooling in the TCM. Direct contact heat sinks are used. The low profile chip carrier in the module having small edge surfaces compared to the top and bottom surfaces of the chip carrier. The module does not have sufficient area on any surface to provide a desired number of conventional pin-in-hole type connectors, and the narrow edges of the TCM do not contain any conductive I/O pins.
An example is the air-cooled thermal conduction module (TCM) constructed with alumina substrates, which is a form of MCM. An upper major surface of the TCM is covered with a thermal cooling structure, and the other major surface is covered with conductive I/O pins which are plugged into a computer framework. The TCM is constructed with many internal layers of wiring to accommodate the interconnections among the chips on the upper TCM surface. The TCM needs only a thin, low-profile shape to contain all needed layers of wiring,and the module shape is also needed to support internal cooling in the TCM. Direct contact heat sinks are used. The result is a low profile module having small edge surfaces compared to the top and bottom surfaces of the module. The TCM does not have sufficient area on any side to provide the desired number of conventional pin-in-hole type connectors, and the narrow edges of the TCM are not used to contain conductive I/O pins.
Prior art connectors, such as disclosed in U.S. Pat. No. 4,553,813 (McNaughton et al), do not disclose any multi-transmission-line array connector, nor any alignment means feasible for an array connector. Also, U.S. Pat. No. 4,553,813 does not provide any connector which can intermix different types of transmission lines, such as optical and electrical, or intermix different types of array connectors for the same module. Further, the connector type in U.S. Pat. No. 4,553,913 cannot connect to a module the large number of transmission lines connectable by the subject invention to an MCM.
This invention provides a means for effecting a pluggable matched impedance connection capability along the top surface of a multilayer ceramic substrate. It employs a unique silicon contact actuation structure coupled to a flexible printed circuit member with an integral elastomeric seal ring. The printed transmission lines thereon terminate to metallic balls soldered to pads on the printed flexible cable which in turn are soldered to pads on a coordinate grid of the MCM substrate.